/*	   $KAME: sha1.c,v 1.3 2000/02/22 14:01:18 itojun Exp $    */

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *	  notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *	  notice, this list of conditions and the following disclaimer in the
 *	  documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *	  may be used to endorse or promote products derived from this software
 *	  without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.	IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * contrib/pgcrypto/sha1.c
 */
/*
 * FIPS pub 180-1: Secure Hash Algorithm (SHA-1)
 * based on: http://www.itl.nist.gov/fipspubs/fip180-1.htm
 * implemented by Jun-ichiro itojun Itoh <itojun@itojun.org>
 */

#include "postgres.h"
#include "knl/knl_variable.h"

#include <sys/param.h>

#include "sha1.h"

/* constant table */
static uint32 _K[] = {0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6};

#define K(t) _K[(t) / 20]

#define F0(b, c, d) (((b) & (c)) | ((~(b)) & (d)))
#define F1(b, c, d) (((b) ^ (c)) ^ (d))
#define F2(b, c, d) (((b) & (c)) | ((b) & (d)) | ((c) & (d)))
#define F3(b, c, d) (((b) ^ (c)) ^ (d))

#define S(n, x) (((x) << (n)) | ((x) >> (32 - (n))))

#define H(n) (ctxt->h.b32[(n)])
#define COUNT (ctxt->count)
#define BCOUNT (ctxt->c.b64[0] / 8)
#define W(n) (ctxt->m.b32[(n)])

#define PUTBYTE(x)                      \
    do {                                \
        ctxt->m.b8[(COUNT % 64)] = (x); \
        COUNT++;                        \
        COUNT %= 64;                    \
        ctxt->c.b64[0] += 8;            \
        if (COUNT % 64 == 0)            \
            sha1_step(ctxt);            \
    } while (0)

#define PUTPAD(x)                       \
    do {                                \
        ctxt->m.b8[(COUNT % 64)] = (x); \
        COUNT++;                        \
        COUNT %= 64;                    \
        if (COUNT % 64 == 0)            \
            sha1_step(ctxt);            \
    } while (0)

static void sha1_step(struct sha1_ctxt*);

static void sha1_step(struct sha1_ctxt* ctxt)
{
    uint32 a, b, c, d, e;
    size_t t, s;
    uint32 tmp;

#ifndef WORDS_BIGENDIAN
    struct sha1_ctxt tctxt;

    memmove(&tctxt.m.b8[0], &ctxt->m.b8[0], 64);
    ctxt->m.b8[0] = tctxt.m.b8[3];
    ctxt->m.b8[1] = tctxt.m.b8[2];
    ctxt->m.b8[2] = tctxt.m.b8[1];
    ctxt->m.b8[3] = tctxt.m.b8[0];
    ctxt->m.b8[4] = tctxt.m.b8[7];
    ctxt->m.b8[5] = tctxt.m.b8[6];
    ctxt->m.b8[6] = tctxt.m.b8[5];
    ctxt->m.b8[7] = tctxt.m.b8[4];
    ctxt->m.b8[8] = tctxt.m.b8[11];
    ctxt->m.b8[9] = tctxt.m.b8[10];
    ctxt->m.b8[10] = tctxt.m.b8[9];
    ctxt->m.b8[11] = tctxt.m.b8[8];
    ctxt->m.b8[12] = tctxt.m.b8[15];
    ctxt->m.b8[13] = tctxt.m.b8[14];
    ctxt->m.b8[14] = tctxt.m.b8[13];
    ctxt->m.b8[15] = tctxt.m.b8[12];
    ctxt->m.b8[16] = tctxt.m.b8[19];
    ctxt->m.b8[17] = tctxt.m.b8[18];
    ctxt->m.b8[18] = tctxt.m.b8[17];
    ctxt->m.b8[19] = tctxt.m.b8[16];
    ctxt->m.b8[20] = tctxt.m.b8[23];
    ctxt->m.b8[21] = tctxt.m.b8[22];
    ctxt->m.b8[22] = tctxt.m.b8[21];
    ctxt->m.b8[23] = tctxt.m.b8[20];
    ctxt->m.b8[24] = tctxt.m.b8[27];
    ctxt->m.b8[25] = tctxt.m.b8[26];
    ctxt->m.b8[26] = tctxt.m.b8[25];
    ctxt->m.b8[27] = tctxt.m.b8[24];
    ctxt->m.b8[28] = tctxt.m.b8[31];
    ctxt->m.b8[29] = tctxt.m.b8[30];
    ctxt->m.b8[30] = tctxt.m.b8[29];
    ctxt->m.b8[31] = tctxt.m.b8[28];
    ctxt->m.b8[32] = tctxt.m.b8[35];
    ctxt->m.b8[33] = tctxt.m.b8[34];
    ctxt->m.b8[34] = tctxt.m.b8[33];
    ctxt->m.b8[35] = tctxt.m.b8[32];
    ctxt->m.b8[36] = tctxt.m.b8[39];
    ctxt->m.b8[37] = tctxt.m.b8[38];
    ctxt->m.b8[38] = tctxt.m.b8[37];
    ctxt->m.b8[39] = tctxt.m.b8[36];
    ctxt->m.b8[40] = tctxt.m.b8[43];
    ctxt->m.b8[41] = tctxt.m.b8[42];
    ctxt->m.b8[42] = tctxt.m.b8[41];
    ctxt->m.b8[43] = tctxt.m.b8[40];
    ctxt->m.b8[44] = tctxt.m.b8[47];
    ctxt->m.b8[45] = tctxt.m.b8[46];
    ctxt->m.b8[46] = tctxt.m.b8[45];
    ctxt->m.b8[47] = tctxt.m.b8[44];
    ctxt->m.b8[48] = tctxt.m.b8[51];
    ctxt->m.b8[49] = tctxt.m.b8[50];
    ctxt->m.b8[50] = tctxt.m.b8[49];
    ctxt->m.b8[51] = tctxt.m.b8[48];
    ctxt->m.b8[52] = tctxt.m.b8[55];
    ctxt->m.b8[53] = tctxt.m.b8[54];
    ctxt->m.b8[54] = tctxt.m.b8[53];
    ctxt->m.b8[55] = tctxt.m.b8[52];
    ctxt->m.b8[56] = tctxt.m.b8[59];
    ctxt->m.b8[57] = tctxt.m.b8[58];
    ctxt->m.b8[58] = tctxt.m.b8[57];
    ctxt->m.b8[59] = tctxt.m.b8[56];
    ctxt->m.b8[60] = tctxt.m.b8[63];
    ctxt->m.b8[61] = tctxt.m.b8[62];
    ctxt->m.b8[62] = tctxt.m.b8[61];
    ctxt->m.b8[63] = tctxt.m.b8[60];
#endif

    a = H(0);
    b = H(1);
    c = H(2);
    d = H(3);
    e = H(4);

    for (t = 0; t < 20; t++) {
        s = t & 0x0f;
        if (t >= 16)
            W(s) = S(1, W((s + 13) & 0x0f) ^ W((s + 8) & 0x0f) ^ W((s + 2) & 0x0f) ^ W(s));
        tmp = S(5, a) + F0(b, c, d) + e + W(s) + K(t);
        e = d;
        d = c;
        c = S(30, b);
        b = a;
        a = tmp;
    }
    for (t = 20; t < 40; t++) {
        s = t & 0x0f;
        W(s) = S(1, W((s + 13) & 0x0f) ^ W((s + 8) & 0x0f) ^ W((s + 2) & 0x0f) ^ W(s));
        tmp = S(5, a) + F1(b, c, d) + e + W(s) + K(t);
        e = d;
        d = c;
        c = S(30, b);
        b = a;
        a = tmp;
    }
    for (t = 40; t < 60; t++) {
        s = t & 0x0f;
        W(s) = S(1, W((s + 13) & 0x0f) ^ W((s + 8) & 0x0f) ^ W((s + 2) & 0x0f) ^ W(s));
        tmp = S(5, a) + F2(b, c, d) + e + W(s) + K(t);
        e = d;
        d = c;
        c = S(30, b);
        b = a;
        a = tmp;
    }
    for (t = 60; t < 80; t++) {
        s = t & 0x0f;
        W(s) = S(1, W((s + 13) & 0x0f) ^ W((s + 8) & 0x0f) ^ W((s + 2) & 0x0f) ^ W(s));
        tmp = S(5, a) + F3(b, c, d) + e + W(s) + K(t);
        e = d;
        d = c;
        c = S(30, b);
        b = a;
        a = tmp;
    }

    H(0) = H(0) + a;
    H(1) = H(1) + b;
    H(2) = H(2) + c;
    H(3) = H(3) + d;
    H(4) = H(4) + e;

    memset(&ctxt->m.b8[0], 0, 64);
}

/*------------------------------------------------------------*/

void sha1_init(struct sha1_ctxt* ctxt)
{
    memset(ctxt, 0, sizeof(struct sha1_ctxt));
    H(0) = 0x67452301;
    H(1) = 0xefcdab89;
    H(2) = 0x98badcfe;
    H(3) = 0x10325476;
    H(4) = 0xc3d2e1f0;
}

void sha1_pad(struct sha1_ctxt* ctxt)
{
    size_t padlen; /* pad length in bytes */
    size_t padstart;

    PUTPAD(0x80);

    padstart = COUNT % 64;
    padlen = 64 - padstart;
    if (padlen < 8) {
        memset(&ctxt->m.b8[padstart], 0, padlen);
        COUNT += padlen;
        COUNT %= 64;
        sha1_step(ctxt);
        padstart = COUNT % 64;  /* should be 0 */
        padlen = 64 - padstart; /* should be 64 */
    }
    memset(&ctxt->m.b8[padstart], 0, padlen - 8);
    COUNT += (padlen - 8);
    COUNT %= 64;
#ifdef WORDS_BIGENDIAN
    PUTPAD(ctxt->c.b8[0]);
    PUTPAD(ctxt->c.b8[1]);
    PUTPAD(ctxt->c.b8[2]);
    PUTPAD(ctxt->c.b8[3]);
    PUTPAD(ctxt->c.b8[4]);
    PUTPAD(ctxt->c.b8[5]);
    PUTPAD(ctxt->c.b8[6]);
    PUTPAD(ctxt->c.b8[7]);
#else
    PUTPAD(ctxt->c.b8[7]);
    PUTPAD(ctxt->c.b8[6]);
    PUTPAD(ctxt->c.b8[5]);
    PUTPAD(ctxt->c.b8[4]);
    PUTPAD(ctxt->c.b8[3]);
    PUTPAD(ctxt->c.b8[2]);
    PUTPAD(ctxt->c.b8[1]);
    PUTPAD(ctxt->c.b8[0]);
#endif
}

void sha1_loop(struct sha1_ctxt* ctxt, const uint8* input0, size_t len)
{
    const uint8* input = NULL;
    size_t gaplen;
    size_t gapstart;
    size_t off;
    size_t copysiz;

    input = (const uint8*)input0;
    off = 0;

    while (off < len) {
        gapstart = COUNT % 64;
        gaplen = 64 - gapstart;

        copysiz = (gaplen < len - off) ? gaplen : len - off;
        memmove(&ctxt->m.b8[gapstart], &input[off], copysiz);
        COUNT += copysiz;
        COUNT %= 64;
        ctxt->c.b64[0] += copysiz * 8;
        if (COUNT % 64 == 0)
            sha1_step(ctxt);
        off += copysiz;
    }
}

void sha1_result(struct sha1_ctxt* ctxt, uint8* digest0)
{
    uint8* digest = NULL;

    digest = (uint8*)digest0;
    sha1_pad(ctxt);
#ifdef WORDS_BIGENDIAN
    memmove(digest, &ctxt->h.b8[0], 20);
#else
    digest[0] = ctxt->h.b8[3];
    digest[1] = ctxt->h.b8[2];
    digest[2] = ctxt->h.b8[1];
    digest[3] = ctxt->h.b8[0];
    digest[4] = ctxt->h.b8[7];
    digest[5] = ctxt->h.b8[6];
    digest[6] = ctxt->h.b8[5];
    digest[7] = ctxt->h.b8[4];
    digest[8] = ctxt->h.b8[11];
    digest[9] = ctxt->h.b8[10];
    digest[10] = ctxt->h.b8[9];
    digest[11] = ctxt->h.b8[8];
    digest[12] = ctxt->h.b8[15];
    digest[13] = ctxt->h.b8[14];
    digest[14] = ctxt->h.b8[13];
    digest[15] = ctxt->h.b8[12];
    digest[16] = ctxt->h.b8[19];
    digest[17] = ctxt->h.b8[18];
    digest[18] = ctxt->h.b8[17];
    digest[19] = ctxt->h.b8[16];
#endif
}
